Pulseless Electrical Activity (PEA) represents one of the most challenging cardiac emergencies healthcare providers encounter. When a patient experiences a PEA arrest, their heart displays electrical activity on the monitor, yet no pulse exists. The proportion of sudden cardiac arrests manifesting with pulseless electrical activity has increased significantly, though survival rates remain lower than ventricular fibrillation. Understanding the reversible causes behind PEA arrests—known as the H's and T's—can mean the difference between life and death. Pulseless electrical activity may have a reversible cause, which can be remembered using the H's and T's mnemonic. This systematic approach helps emergency responders and healthcare professionals quickly identify and treat the underlying causes of PEA arrests. Each letter represents a potentially life-threatening condition that, when identified and corrected promptly, can restore normal cardiac function. The H's: Six ...